Pressure sensitive release device



June 7,1955 Q. FRAZIER ETAL 2,710,218

PRESSURE SENSITIVE RELEASE DEVICE Filed Nov. 3, 1950 FIG. 5.

INVENTORS QUENTIN FRAZIER JAMES M BRADY AND BY PRESSURE SENSITIVE RELEASE DEVICE Quentin Frazier, Red Bank, and James M. Brady, West Long Branch, N. 1., assignors to the United States of America as represented by the Secretary of the Army Application November 3, 1950, Serial No; 194,004

Claims, (Cl; 294-83) (Granted under Title 35, U. S. Code (1952), see. 266) I The invention described herein may be manufactured and used by or for the Government'for governmental purposes, without the payment of any royalty thereon.

The present invention relates to a pressure sensitive release device.

In the utilization and testing of certain meteorological equipment, the necessity often arises that certain equipment be elevated to a certain predetermined altitude and then released. This is particularly true when it is desired to release certain equipment at a predetermined atmospheric pressure above the pressure at sea level.

Accordingly, it is an object of this invention to provide a pressure sensitive release device that will function to release a piece of test equipment or any desired load at a certain predetermined atmospheric pressure.

Another object of the invention is to provide a device with a minimum of moving parts that can be readily and inexpensively assembled.

Another object of the invention is to provide a pressure sensitive release device whose action is positive and instantaneous.

The improved device comprising our invention consists essentially of a pair of arms forming a frame, each of the arms pivotally movable relative to each other, and cooperating to form a releasable locking mechanism at one end, and having within the frame a pressure sensitive responsive element, and further provided with a leaf 2,710,218 Patented June 7, 1955 hook 23, which, when the device is in locked engagement as shown in Fig. 1, form a confining slot for retaining a ring 39 to which is secured the test equipmentor any desired load to be dropped.

Laterally positioned through the crossbar 15 is an adjustment screw 25, serving as a means for supporting a pressure sensitive element 27. In the particular adaptation shown herein, thev pressure sensitive element 27 is in the form of a pair of aneroid cells, in series, of conventional design which expand upon decrease in pressure. By raising or lowering the adjustment screw 25, the aneroid cells can be longitudinally positioned within the frame so as to permit the device to function at varied pressures.

To the bottom of the lowermost aneroid cell, there is suitably secured, as by welding or the like, a knife-edged stud 29, beneath which there is positioned a leaf spring 31 which is fitted between the arms 11 and 13 within notches 33 and 35 respectively. The leaf spring 31 serves to constrain the arms 11, 13, against inward movement, toward each other, when the spring is slightly arced when in engagement with the stud 29, as shown in Fig. 1. It is to be noted that the notches 33, 35, have angulated sides which will permit the leaf spring 31 to assome arcuate positions as shown in Figs. 1 and 2. Proximate to the locking means, formed by the converging arms 11, 13, is a coil tension spring 37 which tends to thus permitting claw 23 to close the open end of slot spring, or similar device acting as a strut between the open and release 'a Fig. l is a front elevational view of a" preferred forrn of release device in closed position;

Fig. 2 is a front elevational view of the release device in open position;

Fig. 3 is front elevational fragmentary view of the device with another type of center supporting means in closed position;

Fig. 4 is a front elevational view of the device shown in Fig. 3 in open position;

Fig. 5 is a fragmentary view of an alternative form of release device embodying the principles of this invention in closed position; and,

Fig. 6 shows the device of Fig. 5 in open position.

. Referring to the drawings, in Fig. 1, there are shown two adjoining arms 11, 13; arm 11 having secured thereto one end of a crossbar 15 by means of screws 17, while the other end of the crossbar 15 is provided with a pivot pin 19, about which the arm 13 is freely pivotable as hereinafter described.

The free end of the arm 11 terminates in a slot 21,

while the free end of the arm 13 terminates in a claw-like 21, restraining ring 39 and the load secured thereto.

For a more detailed view of the functioning of the device, reference is made to Fig. 2, where the release device is shown in releasing position. As the device ascends into the atmosphere, into regions of progressively lower pressure areas, the cells 27 will expand, thereby carrying the stud 29 in a downward direction. When the predetermined pressure area is reached, for which the cells were preset by control of their position within the frame, the leaf spring 31 will snap past dead center posi-' tion, leaving the'arms of the frame unsupported, whereby the coil spring 37 is free to pull the arm 13 inwardly, and thereby displace claw 23 from its locking position, as in Fig. 2, permitting ring 39 to fall freely and carry 1 the load or equipment secured thereto.

In the modification shown in Fig. 3, in lieu of the leaf spring. 31 there is shown. a beam 41 that is center hinged and secured to each of the frame members 11 and 13 by means of pivot pins or the like. The beam operates in a manner similar to that of the leaf spring 31, in that downward displacement caused by the expansion of the aneroid cells will cause beam 41 to assume the position shown in Fig. 4.

For raising the release device into the atmosphere, the device can be secured to a gas-filled balloon. For securing the device to a balloon, we provide an opening 43 in the crossbar, through which a cord 45 can be placed, which in turn issecured to the balloon.

In certain instances, where it is desired to reverse the operation of the pressure sensitive release device, that is, for example, where it is desired to release the device at a relatively high altitude, in a low pressure area, and

a release the test equipment, or any desired load, at a lower altitude or higher pressure area, We propose to use a pressure sensitive release device such as is shown in Figs. 5 and 6. The device shown in Fig. 5 is substantially similar to that as shown in Figs. 1-4, except that there is provided an arm 47, which is secured to the lowermost pressure responsive element, terminating in a claw 19, which claw is in releasable engagement with the underside of a hinged beam 51, which functions in a manner similar to the hinged beam 41 of Fig. 3. However, as the release device is dropped from a plane, at a relatively high altitude, with a parachute attached thereto,,the aneroid cells will be expanded-and as the parachute descends, reaching higher pressure areas, the cells will progressively decrease insize, raising arm 47 upwardly, carrying with it the hinged beam 51. At a certain atmospheric pressure, the hanged beamSl willbe upset and assume the position shown in Fig. 6,- thereby permitting the coil spring 37 to function as hereinbefore described. It is to be understood that in lieu of the hinged beam 51,. of the modification. shown in Figs. 5 and 6,.a leaf spring, similar to the leaf spring 31, may be utilized.

While there have been described what. are at present considered to be the preferred embodiments of this. invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the. invention, andit is, therefore, aimed in the appended claims to cover allv such changes and modifications as fall within. the true spirit and scope of the invention.

What is claimed is:

1. Automatic means for causing a'load to be released at a predetermined pressure,.comprisinga pair of joined arms hinged at one end and forming a frame, one of said arms having affixed-thereto, and withinv said frame, a pressure responsive element that is variable in size to variations in pressure, said armsv forming. a locking means for the load to be released, spring means for urging said arms toward each other, and a leaf spring be tween said arms to constrain said arms against inward movement and responsive to action of. said pressure responsive element whereby said arms will be inlocked or unlocked position upon variations in atmospheric pressure, said leaf spring having an arcuate length greater. than the straight line distance between the arms when said locking means is in locked position and the load is supported.

2. Automatic means for causing a load to be released at a predetermined pressure, comprising a pair. of joined arms forming a substantially tong shaped frame, a pressure responsive element within said frame andaffixed to one of said arms, spring means for. urging saidarms'. t0- ward each. other, one of said arms. having a slot therein,

, the other of said arms having a claw that cooperates with said slot to form a locking means for the load to be released, and a leaf spring betweenxsa-id' arms to constrain said arms against inward movement and responsive to action of said pressure responsive element whereby said arms willbe in locked or unlockedposition upon variations in atmospheric pressure, said leaf spring having an arcuate length greater than the straight line distance between said arms when said locking means is in locked position and the load is supported.

3. Automatic means for causing aload to be'released at a predetermined pressure, comprising a pair of joined arms forming a substantially tong shaped frame, a pressure responsive element within said frame and aflixed to sure the'sum of. the lengths of the members of said beam being'greater than the straight line distance between the armswhen said locking means is in locked position.

4. Automatic means for causing a load to be released at a predetermined pressure, comprising a pair of arms pivotally joined at one end and forming a frame, a pressure responsive element that is variable in size with variations in pressure, affixed to one of said arms and within said frame, said arms forming a locking means for the loadto be released, spring means for urging said arms toward each other and means to constrain said arms against inward movement, said last mentioned means being responsivev to action of. said pressure responsive element whereby said arms will be in locked or unlocked position upon variations in atmospheric pressure, said constraining means having an arched length greater than the straight line distance between the arms when said locking means is in locked position and the load is supported.

5. A. pressure sensitive release device for releasing a load comprising a pair of arms pivotally joined at one end forming a frame, a pressure responsive element that is variable in size withvariations in pressure, aifixed to one of said arms and within said frame, said arms cooperating to form a locking means for supporting said load whenin locked position and for releasing said load when in open position, spring means for urging said arms into open position, a restraining member having a variable eifective length between said arms, said member having an effective length great enough to constrain said arms against. inward movement when said arms are in locked position and said load is supported, said restraining memher being adjacent said pressure responsive element and responsive thereto whereby upon variations in atmospheric pressure the effective length of said member will be reduced to. permit said spring means to urge said arms toward each other into open position thereby releasing said load.

References Cited in the file of this patent UNITED STATES PATENTS 1,294,327 Boston et al. Feb. 11, 1919 1,346,160 Barlow July '13, 1920 2,185,561 Nensteil' Jan. 2, 1940 2,452,990 Bush Nov. 2, 1948 2,470,457 Banc'o'ra May 17, 1949 2,478,138 Tobias Aug. 2, 1949 FOREIGN PATENTS 123,705 Australia Mar. 13, 1947 160,181 Great Britain Apr. 14, 1921 

